Buggy code:
public class AdminActivity extends AppCompatActivity { private ListView mDrawerList ; private ActionBarDrawerToggle mDrawerToggle ; private DrawerLayout mDrawerLayout ; String open_drawer = "Current<seq2seq4repair_space>Section" ; ExpandableListAdapter listAdapter ; ExpandableListView expListView ; ArrayList < String > listDataClass ; HashMap < String , List < String > > listDataChild ; ProgressDialog pDialog ; String username ; String loginUrl ; final String DEFAULT_TITLE = "Classes" ; boolean addQuizMode = false ; final Context context = this ; @ Override protected void onCreate ( Bundle savedInstanceState ) { } class AttemptUpdateClasses extends AsyncTask < String , String , String > { protected void onPreExecute ( ) { } @ Override protected String doInBackground ( String ... params ) { } protected void onPostExecute ( String message ) { } } private void loadClasses ( ) { DbHelperAdminClasses db = new DbHelperAdminClasses ( this ) ; Pair < ArrayList < String > , HashMap < String , List < String > > > pair = db . loadAdminClasses ( username ) ; listDataClass = pair . first ; listDataChild = pair . second ; listAdapter = new ExpandableListAdapter ( this , listDataClass , listDataChild ) ; expListView . setAdapter ( listAdapter ) ; expListView . setOnGroupClickListener ( new ExpandableListView . OnGroupClickListener ( ) { @ Override public boolean onGroupClick ( ExpandableListView parent , View v , int groupPosition , long id ) { if ( addQuizMode ) { addQuizMode = false ; ActionMenuItemView addQuizButton = ( ( ActionMenuItemView ) ( findViewById ( action_add_question ) ) ) ; <START_BUG> addQuizButton . setIcon ( ResourcesCompat . getDrawable ( getResources ( ) , ic_control_point_white_24dp , null ) ) ; <END_BUG> AlertDialog . Builder alertDialogBuilder = new AlertDialog . Builder ( context ) ; alertDialogBuilder . setTitle ( "Your<seq2seq4repair_space>Title" ) ; alertDialogBuilder . setMessage ( ( "Would<seq2seq4repair_space>you<seq2seq4repair_space>like<seq2seq4repair_space>to<seq2seq4repair_space>add<seq2seq4repair_space>a<seq2seq4repair_space>new<seq2seq4repair_space>quiz<seq2seq4repair_space>to<seq2seq4repair_space>" + ( listAdapter . getGroup ( groupPosition ) ) ) ) . setCancelable ( false ) . setPositiveButton ( "Yes" , new DialogInterface . OnClickListener ( ) { public void onClick ( DialogInterface dialog , int id ) { } } ) . setNegativeButton ( "No" , new DialogInterface . OnClickListener ( ) { public void onClick ( DialogInterface dialog , int id ) { dialog . cancel ( ) ; } } ) ; AlertDialog alertDialog = alertDialogBuilder . create ( ) ; alertDialog . show ( ) ; } return false ; } } ) ; expListView . setOnChildClickListener ( new ExpandableListView . OnChildClickListener ( ) { @ Override public boolean onChildClick ( ExpandableListView parent , View v , int groupPosition , int childPosition , long id ) { Intent intent = new Intent ( getApplicationContext ( ) , AdminStartupPageActivity . class ) ; String subject = listDataClass . get ( groupPosition ) ; String classTitle = listDataChild . get ( listDataClass . get ( groupPosition ) ) . get ( childPosition ) ; intent . putExtra ( "title" , classTitle ) ; intent . putExtra ( "username" , username ) ; startActivity ( intent ) ; return false ; } } ) ; } private void addDrawerItems ( ) { } private void setupDrawer ( ) { } @ Override protected void onPostCreate ( Bundle savedInstanceState ) { } @ Override public void onConfigurationChanged ( Configuration newConfig ) { } @ Override public boolean onCreateOptionsMenu ( Menu menu ) { } @ Override public boolean onOptionsItemSelected ( MenuItem item ) { } public void addNewQuizDialogue ( ) { } }

Fix:
addQuizButton . setIcon ( ResourcesCompat . getDrawable ( getResources ( ) , ic_add_white_48dp , null ) ) ;